CN116892011A - Method for protecting metal parts against corrosion using chromium-containing films - Google Patents

Abstract

Embodiments of the present disclosure relate generally to protective coatings on aerospace components and methods for depositing protective coatings. In one or more embodiments, a method of depositing a protective coating on an aerospace component includes sequentially exposing the aerospace component to a chromium precursor and a reactant to deposit a protective coating on a surface of the aerospace component through an atomic layer deposition process. A chromium-containing layer is formed on it. The chromium-containing layer contains metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium silicide, or any combination of the above.

Description

Method for protecting metal parts from corrosion using chromium-containing films

This application is a divisional application of the invention patent application with application number 201980020567.6 filed on March 18, 2019 and invention name “Method for protecting metal parts against corrosion using chromium-containing films”.

Technical Field

Embodiments of the present disclosure relate generally to deposition processes, and particularly to vapor deposition processes for depositing films on aerospace components.

Background Art

Turbine engines typically have components that corrode or degrade over time due to exposure to hot gases and/or reactive chemicals (e.g., acids, bases, or salts). Such turbine components are often protected by thermal and/or chemical barrier coatings. Current coatings used on wings exposed to the hot gases of combustion in gas turbine engines, both for environmental protection and as bond coatings in thermal barrier coating (TBC) systems, include diffusion aluminides and various metal alloy coatings. These coatings are applied to substrate materials (usually nickel-based superalloys) to provide protection against oxidation and corrosion. These coatings are formed on substrates in a number of different ways. For example, a nickel aluminide layer can be grown on a nickel-based superalloy as an outer coating simply by exposing the substrate to an aluminum-rich environment at high temperatures. Aluminum diffuses into the substrate and combines with nickel to form the outer surface of a nickel-aluminum alloy.

A platinum-modified nickel aluminide coating can be formed by first electroplating platinum to a predetermined thickness on a nickel-based substrate. Exposing the platinum-plated substrate to an aluminum-rich environment at high temperature causes the growth of an outer region of a nickel-aluminum alloy containing platinum in solid solution. In the presence of excess aluminum, the platinum-aluminum has two phases that can precipitate in the NiAl matrix when the aluminum diffuses into and reacts with the nickel and platinum.

However, as the demand for increased engine performance increases the operating temperature of the engine and/or the life requirements of the engine, when the coating is used as an environmental coating or as a bonding coating, the performance of the coating is required to be higher than the capabilities of these existing coatings. Due to these requirements, a coating that can be used for environmental protection or can be used as a bonding coating that can withstand higher operating temperatures or operate for a longer period of time before being removed for repair, or both, is needed. These known coating materials and deposition techniques have several disadvantages. Most metal alloy coatings deposited by low-pressure plasma spraying, plasma vapor deposition (plasma vapor deposition; PVD), electron beam physical vapor deposition (electron beam PVD; EBPVD), cathode arc or similar sputtering techniques are line-of-sight coatings, meaning that the inside of the component cannot be coated. External platinum plating usually forms a fairly uniform coating, but it has been proven that plating the inside of the component is challenging. The resulting electroplated coating is often too thin to protect or too thick and there are other adverse mechanical effects, such as excessive weight gain or reduced fatigue life. Similarly, aluminide coatings also suffer from non-uniformity on the internal channels of the component. Aluminide coatings are brittle, which can result in reduced life when exposed to fatigue.

In addition, most of these coatings are greater than about 10 microns thick, which can add weight to the part and make the design of disks and other support structures more challenging. Most of these coatings require high temperature (e.g., greater than 500°C) steps to deposit or promote sufficient interdiffusion of the coating into the alloy to achieve adhesion. Many people desire coatings that: (1) protect the metal from oxidation and corrosion; (2) are capable of high film thickness and composition uniformity on arbitrary geometries; (3) have high adhesion to the metal; (4) are thin enough not to substantially increase weight or reduce fatigue life beyond current design practices for bare metal, and/or (5) are deposited at sufficiently low temperatures (e.g., 500°C or less) not to cause microstructural changes to the metal.

Therefore, there is a need for improved protective coatings and improved methods of depositing protective coatings.

Summary of the invention

Embodiments of the present disclosure generally relate to protective coatings on aerospace components and methods for depositing protective coatings. In one or more embodiments, a method for depositing a protective coating on an aerospace component includes sequentially exposing the aerospace component to a chromium precursor and a reactant to form a chromium-containing layer on a surface of the aerospace component by an atomic layer deposition (ALD) process. The chromium-containing layer comprises metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium silicide, or any combination thereof.

In some embodiments, a method of depositing a coating on an aerospace component includes: forming a nanolaminate film stack on a surface of the aerospace component, wherein the nanolaminate film stack contains alternating layers of a chromium-containing layer and a second deposited layer. The method further includes: sequentially exposing the aerospace component to a chromium precursor and a first reactant to form the chromium-containing layer on the surface by ALD, and sequentially exposing the aerospace component to a metal or silicon precursor and a second reactant to form the second deposited layer on the surface by ALD. The chromium-containing layer comprises chromium oxide, chromium nitride, or a combination thereof; and the second deposited layer comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate, or any combination thereof.

In other embodiments, an aerospace component contains a coating disposed on a surface. The surface includes or contains nickel, a nickel superalloy, aluminum, chromium, iron, titanium, hafnium, an alloy of the foregoing, or a combination of the foregoing. The coating has a thickness of less than 10 μm and includes or contains a chromium-containing layer, and wherein the chromium-containing layer comprises metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium silicide, or any combination of the foregoing. In some instances, the surface of the aerospace component is an inner surface within a cavity of the aerospace component. The cavity may have an aspect ratio of about 5 to about 1,000, and the coating may have a uniformity of less than 30% of the thickness across the inner surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The above briefly summarizes the manner in which the above-recited features of the present disclosure can be understood in detail, as well as a more specific description of the present disclosure, which can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only exemplary embodiments and are therefore not to be considered as limiting the scope of the present invention, as the invention may admit to other equally effective embodiments.

1 is a flow chart of a method of depositing a coating on an aerospace component according to one or more embodiments described and discussed herein.

2 is a schematic diagram of a protective coating disposed on a surface of an aerospace component according to one or more embodiments described and discussed herein.

3A and 3B are schematic illustrations of aerospace components containing one or more protective coatings according to one or more embodiments described and discussed herein.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one or more embodiments may be beneficially incorporated in other embodiments.

DETAILED DESCRIPTION

Embodiments of the present disclosure generally relate to protective coatings, such as nanolaminate film stacks or coalesced films, disposed on aerospace components; and methods of depositing protective coatings. Aerospace components as described and discussed herein may be or include one or more turbine blades, turbine buckets, fins, fins, columnar fins, combustor fuel nozzles, combustor shrouds, or any other aerospace component or part that would benefit from depositing a protective coating thereon. The protective coating may be deposited or otherwise formed on an interior surface and/or exterior surface of an aerospace component.

In one or more embodiments, a method of depositing a protective coating on an aerospace component includes sequentially exposing the aerospace component to a chromium precursor and a reactant to form a chromium-containing layer on a surface of the aerospace component by an atomic layer deposition (ALD) process. The chromium-containing layer includes metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium silicide, or any combination thereof.

In some embodiments, a nanolaminate film stack is formed on the surface of an aerospace component, wherein the nanolaminate film stack contains alternating layers of a chromium-containing layer and a second deposited layer. The aerospace component may be sequentially exposed to a metal or silicon precursor and a second reactant to form a second deposited layer on the surface by ALD. The second deposited layer comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate, or any combination of the foregoing. The nanolaminate film stack comprising alternating layers of a chromium-containing layer and a second deposited layer may be used as a protective coating on an aerospace component. Alternatively, in other embodiments, the nanolaminate film stack disposed on an aerospace component may be exposed to an annealing process to convert the nanolaminate film stack into a coalesced film, which may be used as a protective coating on an aerospace component.

FIG1 is a flow chart of a method 100 for depositing a coating on one or more aerospace components according to one or more embodiments described and discussed herein. FIG2 is a schematic diagram of protective coatings 200 and 250 disposed on a surface of an aerospace component 202 according to one or more embodiments described and discussed herein. Protective coatings 200 and 250 may be deposited or otherwise formed on an aerospace component 202 by the method 100 described and discussed below.

In one or more embodiments, the protective coating 200 contains a nanolaminate film stack 230, which contains one or more pairs of first deposited layers 210 and second deposited layers 220 sequentially deposited or otherwise formed on the aerospace component 202, as shown in (a) of FIG. 2. The nanolaminate film stack 230 is illustrated as having four pairs of first and second deposited layers 210, 220, however, the nanolaminate film stack 230 may include any number of first and second deposited layers 210, 220, as further discussed below. For example, the nanolaminate film stack 230 may contain from one pair of first and second deposited layers 210, 220 to about one hundred and fifty pairs of first and second deposited layers 210, 220. In other embodiments (not shown), the protective coating 200 is not a nanolaminate film stack, but contains a first deposited layer 210 or a second deposited layer 220 deposited or otherwise formed on the aerospace component 202. In further embodiments, a nanolaminate film stack 230 comprising one or more pairs of first and second deposited layers 210 , 220 is first deposited and subsequently converted into a coalesced film 240 , such as illustrated by the protective coating 250 shown in FIG. 2( b ).

At block 110, the aerospace component 202 may optionally be exposed to one or more pre-cleaning processes prior to producing the protective coating 200 or 250. The surface of the aerospace component 202 may contain oxides, organics, oils, dirt, particles, debris, and/or other contaminants that are removed prior to producing the protective coating 200 or 250 on the aerospace component 202. The pre-cleaning process may be or include one or more oiling or texturing processes, vacuum cleaning, solvent cleaning, acid cleaning, wet cleaning, plasma cleaning, ultrasonic treatment, or any combination thereof. Once cleaned and/or textured, the subsequently deposited protective coating 200 or 250 has stronger adhesion to the surface of the aerospace component 202 than if it had not been exposed to the pre-cleaning process.

In one or more examples, the surface of the aerospace component 202 can be blasted or otherwise exposed with beads, sand, carbonates, or other particulates to remove oxides and other contaminants from the surface, and/or to provide texturing to the surface of the aerospace component 202. In some embodiments, the aerospace component 202 can be placed in a chamber within a pulsed push-pull system and exposed to cycles of purge gas (e.g., _N2 , Ar, He, or any combination thereof) and vacuum purge to remove debris from small holes on the aerospace component 202. In other examples, the surface of the aerospace component 202 can be exposed to hydrogen plasma, oxygen or ozone plasma, and/or nitrogen plasma, which can be generated in a plasma chamber or by a remote plasma system.

In one or more examples, such as for organic removal or oxide removal, the surface of the aerospace component 202 may be exposed to a hydrogen plasma, followed by degassing, and subsequently exposed to an ozone treatment. In other examples, such as for organic removal, the surface of the aerospace component 202 may be exposed to a wet cleaning process that includes soaking in an alkaline degreasing solution, rinsing, exposing the surface to an acidic cleaning solution (e.g., sulfuric acid, phosphoric acid, or hydrochloric acid), rinsing, and exposing the surface to a deionized water ultrasonic bath. In some examples, such as for oxide removal, the surface of the aerospace component 202 may be exposed to a wet cleaning process that includes exposing the surface to a dilute acid solution (e.g., acetic acid or hydrochloric acid), rinsing, and exposing the surface to a deionized water ultrasonic bath. In one or more examples, such as for particle removal, the surface of the aerospace component 202 can be exposed to ultrasonic treatment (e.g., supersonic) and/or supercritical carbon dioxide washing, followed by a cycle of exposure to a purge gas (e.g., N ₂ , Ar, He, or any combination thereof) and vacuum purge to remove particles from the surface and dry the surface. In some examples, the aerospace component 202 can be exposed to a heating or drying process, such as heating the aerospace component 202 to a temperature of about 50° C., about 65° C., or about 80° C. to about 100° C., about 120° C., or about 150° C. and exposing the surface to the purge gas. The aerospace component 202 can be heated in a heating furnace or exposed to lamps for the heating or drying process.

At block 120, the aerospace component 202 may be exposed to a first precursor and a first reactant to form a first deposition layer 210 on the aerospace component 202 by a vapor deposition process, as shown in (a) of FIG2. The vapor deposition process may be an ALD process, a plasma-enhanced ALD (PE-ALD) process, a thermal chemical vapor deposition (CVD) process, a plasma-enhanced CVD (PE-CVD) process, or any combination thereof.

In one or more embodiments, the vapor deposition process is an ALD process, and the method includes exposing the surface of the aerospace component 202 to a first precursor and a first reactant to form a first deposition layer 210. Each cycle of the ALD process includes exposing the surface of the aerospace component to the first precursor, performing a pump-purge, exposing the aerospace component to the first reactant, and performing a pump-purge to form the first deposition layer 210. The order of the first precursor and the first reactant may be reversed so that the ALD cycle includes exposing the surface of the aerospace component to the first reactant, performing a pump-purge, exposing the aerospace component to the first precursor, and performing a pump-purge to form the first deposition layer 210.

In some examples, during each ALD cycle, the aerospace component 202 is exposed to the first precursor for about 0.1 seconds to about 10 seconds, to the first reactant for about 0.1 seconds to about 10 seconds, and to the pump-purge for about 0.5 seconds to about 30 seconds. In some examples, during each ALD cycle, the aerospace component 202 is exposed to the first precursor for about 0.5 seconds to about 3 seconds, to the first reactant for about 0.5 seconds to about 3 seconds, and to the pump-purge for about 1 second to about 10 seconds.

Each ALD cycle is repeated from 2 times, 3 times, 4 times, 5 times, 6 times, 8 times, about 10 times, about 12 times, or about 15 times to about 18 times, about 20 times, about 25 times, about 30 times, about 40 times, about 50 times, about 65 times, about 80 times, about 100 times, about 120 times, about 150 times, about 200 times, about 250 times, about 300 times, about 350 times, about 400 times, about 500 times, about 800 times, about 1,000 times, or more to form the first deposition layer. For example, each ALD cycle is repeated from 2 times to about 1,000 times, 2 times to about 800 times, 2 times to about 500 times, 2 times to about 300 times, 2 times to about 250 times, 2 times to about 200 times, 2 times to about 150 times, 2 times to about 120 times, 2 times to about 100 times, 2 times to about 80 times, 2 times to about 50 times, 2 times to about 30 times, 2 times to about 20 times, 2 times to about 15 times, 2 times to about 10 times, 2 times to about 50 times, 2 times to about 30 times, 2 times to about 20 times, 2 times to about 15 times, 2 times to about 10 times, 2 times to 5 times, about 8 times to about 1,000 times, about 8 times to about 800 times, about 8 times to about 500 times, about 8 times to about 300 times, about 8 times to about 250 times, about 8 times to about 200 times, about 8 times to about 150 times, about 8 times to about 120 times, about 8 times to about 100 times, about 8 times to about 80 times, about 8 times to about 50 times, From about 8 times to about 30 times, from about 8 times to about 20 times, from about 8 times to about 15 times, from about 8 times to about 10 times, from about 20 times to about 1,000 times, from about 20 times to about 800 times, from about 20 times to about 500 times, from about 20 times to about 300 times, from about 20 times to about 250 times, from about 20 times to about 200 times, from about 20 times to about 150 times, from about 20 times to about 120 times, from about 20 times to about 100 times, from about 20 times to about 80 times, from about 20 times to about 50 times, from about 20 times to about 30 times, from about 50 times to about 1,000 times, from about 50 times to about 500 times, from about 50 times to about 350 times, from about 50 times to about 300 times, from about 50 times to about 250 times, from about 50 times to about 150 times, or from about 50 times to about 100 times to form the first deposition layer 210.

In other embodiments, the vapor deposition process is a CVD process, and the method includes exposing the aerospace component 202 to a first precursor and a first reactant simultaneously to form the first deposited layer 210. During the ALD process or the CVD process, each of the first precursor and the first reactant may independently include one or more carrier gases. Between the exposure of the first precursor and the first reactant, one or more purge gases may be flowed across the aerospace component and/or throughout the processing chamber. In some examples, the same gas may be used as a carrier gas or a purge gas. Exemplary carrier gases and purge gases may independently be or include one or more of nitrogen ( _N2 ), argon, helium, neon, hydrogen ( _H2 ), or any combination of the foregoing.

The first deposition layer 210 may have a thickness of about 0.1 nm, about 0.2 nm, about 0.3 nm, about 0.4 nm, about 0.5 nm, about 0.8 nm, about 1 nm, about 2 nm, about 3 nm, about 5 nm, about 8 nm, about 10 nm, about 12 nm, or about 15 nm to about 18 nm, about 20 nm, about 25 nm, about 30 nm, about 40 nm, about 50 nm, about 60 nm, about 80 nm, about 100 nm, about 120 nm, or about 150 nm. For example, the first deposition layer 210 may have a thickness of about 0.1 nm to about 150 nm, about 0.2 nm to about 150 nm, about 0.2 nm to about 120 nm, about 0.2 nm to about 100 nm, about 0.2 nm to about 80 nm, about 0.2 nm to about 50 nm, about 0.2 nm to about 40 nm, about 0.2 nm to about 30 nm, about 0.2 nm to about 20 nm, about 0.2 nm to about 10 nm, about 0.2 nm to about 5 nm, about 0.2 nm to about 1 nm, about 0.2 nm to about 0.5 nm, about 0.5 nm to about 150 nm, about 0.5 nm to about 120 nm, about 0.5 nm to about 100 nm, about 0.5 ...5 nm to about 50 nm, about 0.5 nm to about 40 nm, about 0.5 nm to about 30 nm, about 0.2 nm to about The thickness of the present invention is from about 5 nm to about 20 nm, from about 0.5 nm to about 10 nm, from about 0.5 nm to about 5 nm, from about 0.5 nm to about 1 nm, from about 2 nm to about 150 nm, from about 2 nm to about 120 nm, from about 2 nm to about 100 nm, from about 2 nm to about 80 nm, from about 2 nm to about 50 nm, from about 2 nm to about 40 nm, from about 2 nm to about 30 nm, from about 2 nm to about 20 nm, from about 2 nm to about 10 nm, from about 2 nm to about 5 nm, from about 2 nm to about 3 nm, from about 10 nm to about 150 nm, from about 10 nm to about 120 nm, from about 10 nm to about 100 nm, from about 10 nm to about 80 nm, from about 10 nm to about 50 nm, from about 10 nm to about 40 nm, from about 10 nm to about 30 nm, from about 10 nm to about 20 nm, or from about 10 nm to about 15 nm.

In one or more embodiments, the first precursor contains one or more chromium precursors, one or more aluminum precursors, or one or more hafnium precursors. The first reactant contains one or more reducing agents, one or more oxidizing agents, one or more nitriding agents, one or more silicon precursors, one or more carbon precursors, or any combination thereof. In some examples, the first deposited layer 210 is a chromium-containing layer, which may be or include metallic chromium, chromium oxide, chromium nitride, chromium silicide, chromium carbide, or any combination thereof. In other examples, the first deposited layer 210 is an aluminum-containing layer, which may be or include metallic aluminum, aluminum oxide, aluminum nitride, aluminum silicide, aluminum carbide, or any combination thereof. In further examples, the first deposited layer 210 is a hafnium-containing layer, which may be or include metallic hafnium, hafnium oxide, hafnium nitride, hafnium silicide, hafnium carbide, or any combination thereof.

The chromium precursor may be or include one or more of a cyclopentadienyl chromium compound, a carbonyl chromium compound, an acetylacetonate chromium compound, a diazadienoate chromium compound, substitutions thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof. Exemplary chromium precursors can be or include bis(cyclopentadienyl)chromium (Cp ₂ Cr), bis(pentamethylcyclopentadienyl)chromium ((Me ₅ Cp) ₂ Cr), bis(isopropylcyclopentadienyl)chromium ((iPrCp) ₂ Cr), bis(ethylbenzene)chromium ((EtBz) ₂ Cr), hexacarbonylchromium (Cr(CO) ₆ ), chromium acetylacetonate (Cr(acac) ₃ , also known as tris(2,4-pentanedione)chromium), hexafluoroacetylacetonate chromium (Cr(hfac) ₃ ), tris(2,2,6,6-tetramethyl-3,5-heptanedione)chromium(III) {Cr(tmhd) ₃ }, bis(1,4-di-tert-butyldiazadienyl)chromium(II), isomers thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof. Exemplary chromium dinitrogen compounds may have the following formula:

Wherein each R and R' is independently selected from H, C1-C6 alkyl, aryl, acyl, alkylamide, hydrazide, silyl, aldehyde, keto, C2-C4 alkenyl, alkynyl or a substituent thereof. In some examples, each R is independently selected from a C1-C6 alkyl group selected from a methyl, ethyl, propyl, butyl or an isomer thereof, and R' is H. For example, R is methyl and R' is H, R is ethyl and R' is H, R is isopropyl and R' is H or R is tert-butyl and R' is H.

The aluminum precursor may be or include one or more alkyl aluminum compounds, one or more alkoxy aluminum compounds, one or more acetylacetonate aluminum compounds, substitutes thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof. Exemplary aluminum precursors may be or include trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, trimethoxyaluminum, triethoxyaluminum, tripropoxyaluminum, tributoxyaluminum, acetylacetonate aluminum (Al(acac) ₃ , also known as tris(2,4-pentanedione)aluminum), hexafluoroacetylacetonate aluminum (Al(hfac) ₃ ), tris-di-pivaloylmethylaluminum (DPM ₃ Al; (C ₁₁ H ₁₉ O ₂ ) ₃ Al), isomers thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof.

The hafnium precursor may be or include one or more cyclopentadienyl hafnium compounds, one or more amino hafnium compounds, one or more alkyl hafnium compounds, one or more alkoxy hafnium compounds, substitutions thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof. Exemplary hafnium precursors can be or include bis(methylcyclopentadienyl)dimethyl hafnium ((MeCp) ₂ HfMe ₂ ), bis(methylcyclopentadienyl)methylmethoxy hafnium ((MeCp) ₂ Hf(OMe)(Me)), bis(cyclopentadienyl)dimethyl hafnium ((Cp) ₂ HfMe ₂ ), tetra(tert-butoxy)hafnium, hafnium isopropoxide ((iPrO) ₄ Hf), tetrakis(dimethylamino)hafnium (TDMAH), tetrakis(diethylamino)hafnium (TDEAH), tetrakis(ethylmethylamino)hafnium (TEMAH), isomers thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof.

The titanium precursor may be or include one or more cyclopentadienyl titanium compounds, one or more amino titanium compounds, one or more alkyl titanium compounds, one or more alkoxy titanium compounds, substituents thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof. Exemplary titanium precursors may be or include bis(methylcyclopentadienyl)dimethyltitanium ((MeCp) ₂ TiMe ₂ ), bis(methylcyclopentadienyl)methylmethoxytitanium ((MeCp) ₂ Ti(OMe)(Me)), bis(cyclopentadienyl)dimethyltitanium ((Cp) ₂ TiMe ₂ ), tetra(tert-butoxy)titanium, isopropoxytitanium ((iPrO) ₄ Ti), tetra(dimethylamino)titanium (TDMAT), tetra(diethylamino)titanium (TDEAT), tetra(ethylmethylamino)titanium (TEMAT), isomers thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof.

In one or more examples, the first deposited layer 210 is a chromium-containing layer that may be or include metallic chromium, and the first reactant contains one or more reducing agents. In some examples, the first deposited layer 210 is an aluminum-containing layer that may be or include metallic aluminum, and the first reactant contains one or more reducing agents. In other examples, the first deposited layer 210 is a hafnium-containing layer that may be or include metallic hafnium, and the first reactant contains one or more reducing agents. Exemplary reducing agents may be or include hydrogen (H ₂ ), ammonia, hydrazine, one or more hydrazine compounds, one or more alcohols, cyclohexadiene, dihydropyrazine, aluminum-containing compounds, extensions of the foregoing, salts of the foregoing, plasma derivatives of the foregoing, or any combination of the foregoing.

In some examples, the first deposited layer 210 is a chromium-containing layer that may be or include chromium oxide, and the first reactant contains one or more oxidants. In other examples, the first deposited layer 210 is an aluminum-containing layer that may be or include aluminum oxide, and the first reactant contains one or more oxidants. In further examples, the first deposited layer 210 is a hafnium-containing layer that may be or include hafnium oxide, and the first reactant contains one or more oxidants. Exemplary oxidants may be or include water (e.g., steam), oxygen (O ₂ ), atomic oxygen, ozone, nitrous oxide, one or more peroxides, one or more alcohols, plasmas of the foregoing, or any combination thereof.

In one or more examples, the first deposited layer 210 is a chromium-containing layer that may be or include chromium nitride, and the first reactant contains one or more nitriding agents. In other examples, the first deposited layer 210 is an aluminum-containing layer that may be or include aluminum nitride, and the first reactant contains one or more nitriding agents. In some examples, the first deposited layer 210 is a hafnium-containing layer that may be or include hafnium nitride, and the first reactant contains one or more nitriding agents. Exemplary nitriding agents may be or include ammonia, atomic nitrogen, one or more hydrazines, nitric oxide, plasmas of the foregoing, or any combination of the foregoing.

In one or more examples, the first deposited layer 210 is a chromium-containing layer that may be or include chromium silicide, and the first reactant contains one or more silicon precursors. In some examples, the first deposited layer 210 is an aluminum-containing layer that may be or include aluminum silicide, and the first reactant contains one or more silicon precursors. In other examples, the first deposited layer 210 is a hafnium-containing layer that may be or include hafnium silicide, and the first reactant contains one or more silicon precursors. Exemplary silicon precursors may be or include silane, disilane, trisilane, tetrasilane, pentasilane, hexasilane, monochlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, hexachlorosilane, substituted silanes, plasma derivatives of the foregoing, or any combination of the foregoing.

In some examples, the first deposited layer 210 is a chromium-containing layer that may be or include chromium carbide, and the first reactant contains one or more carbon precursors. In other examples, the first deposited layer 210 is an aluminum-containing layer that may be or include aluminum carbide, and the first reactant contains one or more carbon precursors. In further examples, the first deposited layer 210 is a hafnium-containing layer that may be or include hafnium carbide, and the first reactant contains one or more carbon precursors. Exemplary carbon precursors may be or include one or more alkanes, one or more alkenes, one or more alkynes, substituents of the foregoing, plasmas of the foregoing, or any combination of the foregoing.

At block 130, the aerospace component 202 is exposed to a second precursor and a second reactant to form a second deposition layer 220 on the first deposition layer 210 by an ALD process, thereby producing a nanolaminate film. The first deposition layer 210 and the second deposition layer 220 have different compositions from each other. In some examples, the first precursor is a different precursor from the second precursor, such as the first precursor is a source of a first type of metal and the second precursor is a source of a second type of metal, and the first and second types of metals are different.

The second precursor may be or include one or more aluminum precursors, one or more hafnium precursors, one or more yttrium precursors, or any combination thereof. The second reactant may be any other reactant used as the first reactant. For example, as described and discussed above, the second reactant may be or include one or more reducing agents, one or more oxidizing agents, one or more nitriding agents, one or more silicon precursors, one or more carbon precursors, or any combination thereof. During the ALD process, each of the second precursor and the second reactant may independently include one or more carrier gases. Between exposure of the second precursor and the second reactant, one or more purge gases may be flowed across the aerospace component and/or throughout the processing chamber. In some instances, the same gas may be used as a carrier gas or a purge gas. Exemplary carrier gases and purge gases may independently be or include one or more of nitrogen (N ₂ ), argon, helium, neon, hydrogen (H ₂ ), or any combination thereof.

In one or more embodiments, the second deposition layer 220 comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate, or any combination thereof. In one or more examples, if the first deposition layer 210 contains aluminum oxide or aluminum nitride, the second deposition layer 220 does not contain aluminum oxide or aluminum nitride. Similarly, if the first deposition layer 210 contains hafnium oxide or hafnium nitride, the second deposition layer 220 does not contain hafnium oxide or hafnium nitride.

Each cycle of the ALD process includes exposing the aerospace component to the second precursor, performing a pump-purge, exposing the aerospace component to the second reactant, and performing a pump-purge to form the second deposition layer 220. The order of the second precursor and the second reactant can be reversed so that the ALD cycle includes exposing the surface of the aerospace component to the second reactant, performing a pump-purge, exposing the aerospace component to the second precursor, and performing a pump-purge to form the second deposition layer 220.

In one or more examples, during each ALD cycle, the aerospace component 202 is exposed to the second precursor for about 0.1 seconds to about 10 seconds, to the second reactant for about 0.1 seconds to about 10 seconds, and to the pump-purge for about 0.5 seconds to about 30 seconds. In some examples, during each ALD cycle, the aerospace component 202 is exposed to the second precursor for about 0.5 seconds to about 3 seconds, to the second reactant for about 0.5 seconds to about 3 seconds, and to the pump-purge for about 1 second to about 10 seconds.

Each ALD cycle is repeated from 2 times, 3 times, 4 times, 5 times, 6 times, 8 times, about 10 times, about 12 times, or about 15 times to about 18 times, about 20 times, about 25 times, about 30 times, about 40 times, about 50 times, about 65 times, about 80 times, about 100 times, about 120 times, about 150 times, about 200 times, about 250 times, about 300 times, about 350 times, about 400 times, about 500 times, about 800 times, about 1,000 times or more to form the second deposition layer 220. For example, each ALD cycle is repeated from 2 times to about 1,000 times, 2 times to about 800 times, 2 times to about 500 times, 2 times to about 300 times, 2 times to about 250 times, 2 times to about 200 times, 2 times to about 150 times, 2 times to about 120 times, 2 times to about 100 times, 2 times to about 80 times, 2 times to about 50 times, 2 times to about 30 times, 2 times to about 20 times, 2 times to about 15 times, 2 times to about 10 times, 2 times to about 50 times, 2 times to about 30 times, 2 times to about 20 times, 2 times to about 15 times, 2 times to about 10 times, 2 times to 5 times, about 8 times to about 1,000 times, about 8 times to about 800 times, about 8 times to about 500 times, about 8 times to about 300 times, about 8 times to about 250 times, about 8 times to about 200 times, about 8 times to about 150 times, about 8 times to about 120 times, about 8 times to about 100 times, about 8 times to about 80 times, about 8 times to about 50 times, From about 8 times to about 30 times, from about 8 times to about 20 times, from about 8 times to about 15 times, from about 8 times to about 10 times, from about 20 times to about 1,000 times, from about 20 times to about 800 times, from about 20 times to about 500 times, from about 20 times to about 300 times, from about 20 times to about 250 times, from about 20 times to about 200 times, from about 20 times to about 150 times, from about 20 times to about 120 times, from about 20 times to about 100 times, from about 20 times to about 80 times, from about 20 times to about 50 times, from about 20 times to about 30 times, from about 50 times to about 1,000 times, from about 50 times to about 500 times, from about 50 times to about 350 times, from about 50 times to about 300 times, from about 50 times to about 250 times, from about 50 times to about 150 times, or from about 50 times to about 100 times to form the second deposition layer 220.

The second deposition layer 220 may have a thickness of about 0.1 nm, about 0.2 nm, about 0.3 nm, about 0.4 nm, about 0.5 nm, about 0.8 nm, about 1 nm, about 2 nm, about 3 nm, about 5 nm, about 8 nm, about 10 nm, about 12 nm, or about 15 nm to about 18 nm, about 20 nm, about 25 nm, about 30 nm, about 40 nm, about 50 nm, about 60 nm, about 80 nm, about 100 nm, about 120 nm, or about 150 nm. For example, the second deposition layer 220 may have a thickness of about 0.1 nm to about 150 nm, about 0.2 nm to about 150 nm, about 0.2 nm to about 120 nm, about 0.2 nm to about 100 nm, about 0.2 nm to about 80 nm, about 0.2 nm to about 50 nm, about 0.2 nm to about 40 nm, about 0.2 nm to about 30 nm, about 0.2 nm to about 20 nm, about 0.2 nm to about 10 nm, about 0.2 nm to about 5 nm, about 0.2 nm to about 1 nm, about 0.2 nm to about 0.5 nm, about 0.5 nm to about 150 nm, about 0.5 nm to about 120 nm, about 0.5 nm to about 100 nm, about 0.5 ...5 nm to about 50 nm, about 0.5 nm to about 40 nm, about 0.5 nm to about 30 nm, about 0.2 nm to about The thickness of the present invention is from about 5 nm to about 20 nm, from about 0.5 nm to about 10 nm, from about 0.5 nm to about 5 nm, from about 0.5 nm to about 1 nm, from about 2 nm to about 150 nm, from about 2 nm to about 120 nm, from about 2 nm to about 100 nm, from about 2 nm to about 80 nm, from about 2 nm to about 50 nm, from about 2 nm to about 40 nm, from about 2 nm to about 30 nm, from about 2 nm to about 20 nm, from about 2 nm to about 10 nm, from about 2 nm to about 5 nm, from about 2 nm to about 3 nm, from about 10 nm to about 150 nm, from about 10 nm to about 120 nm, from about 10 nm to about 100 nm, from about 10 nm to about 80 nm, from about 10 nm to about 50 nm, from about 10 nm to about 40 nm, from about 10 nm to about 30 nm, from about 10 nm to about 20 nm, or from about 10 nm to about 15 nm.

In some examples, the first deposition layer 210 is a chromium-containing layer containing chromium oxide, chromium nitride, or a combination thereof; and the second deposition layer 220 contains one or more of aluminum oxide, aluminum nitride, hafnium oxide, hafnium silicate, titanium oxide, or any combination thereof.

At block 140, the method 100 includes determining whether the desired thickness of the nano-lambda film stack 230 has been achieved. If the desired thickness of the nano-lambda film stack 230 has been achieved, then move to block 150. If the desired thickness of the nano-lambda film stack 230 has not been achieved, then another deposition cycle is started: namely, the first deposition layer 210 is deposited by a vapor deposition process at block 120, and the second deposition layer 220 is deposited by an ALD process at block 130. The deposition cycle is repeated until the desired thickness of the nano-lambda film stack 230 is achieved.

In one or more embodiments, the protective coating 200 or the nanolaminate film stack 230 may contain from 1, 2, 3, 4, 5, 6, 7, 8, or 9 pairs of first and second deposited layers 210, 220 to about 10, about 12, about 15, about 20, about 25, about 30, about 40, about 50, about 65, about 80, about 100, about 120, about 150, about 200, about 250, about 300, about 500, about 800, or about 1,000 pairs of first and second deposited layers 210, 220. For example, the nanolaminate film stack 230 may include 1 pair to about 1,000 pairs, 1 pair to about 800 pairs, 1 pair to about 500 pairs, 1 pair to about 300 pairs, 1 pair to about 250 pairs, 1 pair to about 200 pairs, 1 pair to about 150 pairs, 1 pair to about 120 pairs, 1 pair to about 100 pairs, 1 pair to about 80 pairs, 1 pair to about 65 pairs, 1 pair to about 50 pairs, 1 pair to about 30 pairs, 1 pair to about 20 pairs, 1 pair to about 15 pairs, 1 pair to about 10 pairs, 1 pair to about 8 pairs, 1 pair to about 6 pairs, 1 pair to about 10 pairs, 1 pair to about 8 pairs, 1 pair to about 6 pairs, 1 pair to about 5 pairs, 1 pair to about 4 pairs, 1 pair to 3 pairs, about 5 pairs to about 150 pairs, about 5 pairs to about 120 pairs, From about 5 pairs to about 100 pairs, from about 5 pairs to about 80 pairs, from about 5 pairs to about 65 pairs, from about 5 pairs to about 50 pairs, from about 5 pairs to about 30 pairs, from about 5 pairs to about 20 pairs, from about 5 pairs to about 15 pairs, from about 5 pairs to about 10 pairs, from about 5 pairs to about 8 pairs, from about 5 pairs to about 7 pairs, from about 10 pairs to about 150 pairs, from about 10 pairs to about 120 pairs, from about 10 pairs to about 100 pairs, from about 10 pairs to about 80 pairs, from about 10 pairs to about 65 pairs, from about 10 pairs to about 50 pairs, from about 10 pairs to about 30 pairs, from about 10 pairs to about 20 pairs, from about 10 pairs to about 15 pairs or from about 10 pairs to about 12 pairs of the first and second deposition layers 210, 220.

The protective coating 200 or the nanolaminate film stack 230 may have a thickness of about 1 nm, about 2 nm, about 3 nm, about 5 nm, about 8 nm, about 10 nm, about 12 nm, about 15 nm, about 20 nm, about 30 nm, about 50 nm, about 60 nm, about 80 nm, about 100 nm, or about 120 nm to about 150 nm, about 180 nm, about 200 nm, about 250 nm, about 300 nm, about 350 nm, about 400 nm, about 500 nm, about 800 nm, about 1,000 nm, about 2,000 nm, about 3,000 nm, about 4,000 nm, about 5,000 nm, about 6,000 nm, about 7,000 nm, about 8,000 nm, about 9,000 nm, or about 10,000 nm, or more. In some examples, the protective coating 200 or the nanolaminate film stack 230 may have a thickness of less than 10 μm (eg, less than 10,000 nm). For example, the protective coating 200 or the nanolaminate film stack 230 may have a thickness of about 1 nm to less than 10,000 nm, about 1 nm to about 8,000 nm, about 1 nm to about 6,000 nm, about 1 nm to about 5,000 nm, about 1 nm to about 3,000 nm, about 1 nm to about 2,000 nm, about 1 nm to about 1,500 nm, about 1 nm to about 1,000 nm, about 1 nm to about 500 nm, about 1 nm to about 400 nm, about 1 nm to about 300 nm, about 1 nm to about 250 nm, about 1 nm to about 200 nm, about 1 nm to about 150 nm, about 1 nm to about 100 nm, about 1 nm to about 80 nm, about 1 nm to about 50 nm, about 20 nm to about 500 nm, about 20 nm to about 400 nm, about 20 nm to about 300 nm, about 20 nm to about 250 nm, about 20 nm to about 200 nm, about 20 nm to about In some embodiments, the thickness of the present invention is from about 1 nm to about 150 nm, from about 20 nm to about 100 nm, from about 20 nm to about 80 nm, from about 20 nm to about 50 nm, from about 30 nm to about 400 nm, from about 30 nm to about 200 nm, from about 50 nm to about 500 nm, from about 50 nm to about 400 nm, from about 50 nm to about 300 nm, from about 50 nm to about 250 nm, from about 50 nm to about 200 nm, from about 50 nm to about 150 nm, from about 50 nm to about 100 nm, from about 80 nm to about 250 nm, from about 80 nm to about 200 nm, from about 80 nm to about 150 nm, from about 80 nm to about 100 nm, from about 50 nm to about 80 nm, from about 100 nm to about 500 nm, from about 100 nm to about 400 nm, from about 100 nm to about 300 nm, from about 100 nm to about 250 nm, from about 100 nm to about 200 nm, or from about 100 nm to about 150 nm.

At block 150, the nanolaminate film stack 230 may be exposed to one or more annealing processes, as appropriate. In some examples, the nanolaminate film stack 230 may be transformed into a coalesced film 240 during the annealing process. During the annealing process, the high temperature coalesces the layers within the nanolaminate film stack 230 into a single structure, in which the new crystalline assembly enhances the integrity and protection of the coalesced film 240. In other examples, the nanolaminate film stack 230 may be heated and densified during the annealing process, but still remain as a nanolaminate film stack. The annealing process may be or include thermal annealing, plasma annealing, ultraviolet annealing, laser annealing, or any combination thereof.

The nanolaminate film stack 230 disposed on the aerospace component 202 is heated to a temperature of about 400° C., about 500° C., about 600° C., or about 700° C. to about 750° C., about 800° C., about 900° C., about 1,000° C., about 1,100° C., about 1,200° C., or more during the annealing process. For example, the nanolaminate film stack 230 disposed on the aerospace component 202 is heated to a temperature of about 400° C. to about 1,200° C., about 400° C. to about 1,100° C., about 400° C. to about 1,000° C., about 400° C. to about 900° C., about 400° C. to about 800° C., about 400° C. to about 700° C., about 400° C. to about 600° C., about 400° C. to about 500° C., about 550° C. to about 1,200° C., about 550° C. to about 1,100° C., about 550° C. to about 1,200° C. The present invention relates to a temperature of about 500°C to about 900°C, about 550°C to about 800°C, about 550°C to about 700°C, about 550°C to about 600°C, about 700°C to about 1,200°C, about 700°C to about 1,100°C, about 700°C to about 1,000°C, about 700°C to about 900°C, about 700°C to about 800°C, about 850°C to about 1,200°C, about 850°C to about 1,100°C, about 850°C to about 1,000°C, or about 850°C to about 900°C.

During the annealing process, the nanolaminate film stack 230 may be in a vacuum at a low pressure (e.g., from 0.1 Torr to less than 760 Torr), at an ambient pressure (e.g., about 760 Torr), and/or at a high pressure (e.g., from greater than 760 Torr (1 atm) to about 3,678 Torr (about 5 atm)). During the annealing process, the nanolaminate film stack 230 may be exposed to an atmosphere containing one or more gases. Exemplary gases used during the annealing process may be or include nitrogen (N ₂ ), argon, helium, hydrogen (H ₂ ), oxygen (O ₂ ), or any combination of the foregoing gases. The annealing process may be performed for about 0.01 seconds to about 10 minutes. In some examples, the annealing process may be a thermal anneal and lasts from about 1 minute, about 5 minutes, about 10 minutes, about 30 minutes to about 1 hour, about 2 hours, about 5 hours, or about 24 hours. In other examples, the annealing process may be a laser anneal or a spike anneal and last from about 1 millisecond, about 100 milliseconds, or about 1 second to about 5 seconds, about 10 seconds, or about 15 seconds.

The protective coating 250 or the coalescing film 240 may have a thickness of about 1 nm, about 2 nm, about 3 nm, about 5 nm, about 8 nm, about 10 nm, about 12 nm, about 15 nm, about 20 nm, about 30 nm, about 50 nm, about 60 nm, about 80 nm, about 100 nm, or about 120 nm to about 150 nm, about 180 nm, about 200 nm, about 250 nm, about 300 nm, about 350 nm, about 400 nm, about 500 nm, about 600 nm, about 800 nm, about 1000 nm, or about 1200 nm to about 1500 nm, about 1800 nm, about 2000 nm, about 2500 nm, about 3000 nm, about 3500 nm, about 4000 nm, about 5000 nm, about 6000 nm, about 7000 nm, about 7000 nm, about 8 ... In some examples, protective coating 250 or coalescing film 240 may have a thickness of less than 10 μm (e.g., less than 10,000 nm). For example, the protective coating 250 or the coalesced film 240 may have a thickness of about 1 nm to less than 10,000 nm, about 1 nm to about 8,000 nm, about 1 nm to about 6,000 nm, about 1 nm to about 5,000 nm, about 1 nm to about 3,000 nm, about 1 nm to about 2,000 nm, about 1 nm to about 1,500 nm, about 1 nm to about 1,000 nm, about 1 nm to about 500 nm, about 1 nm to about 400 nm, about 1 nm to about 300 nm, about 1 nm to about 250 nm, about 1 nm to about 200 nm, about 1 nm to about 150 nm, about 1 nm to about 100 nm, about 1 nm to about 80 nm, about 1 nm to about 50 nm, about 20 nm to about 500 nm, about 20 nm to about 400 nm, about 20 nm to about 300 nm, about 20 nm to about 250 nm, about 20 nm to about 200 nm, about 20 nm to about A thickness of about 150 nm, about 20 nm to about 100 nm, about 20 nm to about 80 nm, about 20 nm to about 50 nm, about 30 nm to about 400 nm, about 30 nm to about 200 nm, about 50 nm to about 500 nm, about 50 nm to about 400 nm, about 50 nm to about 300 nm, about 50 nm to about 250 nm, about 50 nm to about 200 nm, about 50 nm to about 150 nm, about 50 nm to about 100 nm, about 80 nm to about 250 nm, about 80 nm to about 200 nm, about 80 nm to about 150 nm, about 80 nm to about 100 nm, about 50 nm to about 80 nm, about 100 nm to about 500 nm, about 100 nm to about 400 nm, about 100 nm to about 300 nm, about 100 nm to about 250 nm, about 100 nm to about 200 nm, or about 100 nm to about 150 nm.

In one or more embodiments, the protective coatings 200 and 250 may have a relatively high uniformity. The protective coatings 200 and 250 may have a uniformity of less than 50%, less than 40%, or less than 30% of the thickness of the respective protective coatings 200, 250. The protective coatings 200 and 250 may independently have a uniformity of about 0%, about 0.5%, about 1%, about 2%, about 3%, about 5%, about 8%, or about 10% to about 12%, about 15%, about 18%, about 20%, about 22%, about 25%, about 28%, about 30%, about 35%, about 40%, about 45%, or less than 50% of the thickness. For example, the protective coatings 200 and 250 can independently have a thickness of about 0% to about 50%, about 0% to about 40%, about 0% to about 30%, about 0% to less than 30%, about 0% to about 28%, about 0% to about 25%, about 0% to about 20%, about 0% to about 15%, about 0% to about 10%, about 0% to about 8%, about 0% to about 5%, about 0% to about 3%, about 0% to about 2%, about 0% to about 1%, about 1% to about 50%, about 1% to about 40%, about 1% to about 30%, about 1% to less than 30%, about 1% to about 28%, about 1% to about 25%, about 1% to about 20%, about 1% to about 15%, about 1% to about 10%, about 0% to about 8%, about 0% to about 5%, about 0% to about 3%, about 0% to about 2%, about 0% to about 1%, about 1% to about 50%, about 1% to about 40%, about 1% to about 30%, about 1% to less than 30%, about 1% to about 28%, about 1% to about 25%, about 1% to about 20%, about 1% to about 15%, about 1% to about 10%. To about 10%, about 1% to about 8%, about 1% to about 5%, about 1% to about 3%, about 1% to about 2%, about 5% to about 50%, about 5% to about 40%, about 5% to about 30%, about 5% to less than 30%, about 5% to about 28%, about 5% to about 25%, about 5% to about 20%, about 5% to about 15%, about 5% to about 10%, about 5% to about 8%, about 10% to about 50%, about 10% to about 40%, about 10% to about 30%, about 10% to less than 30%, about 10% to about 28%, about 10% to about 25%, about 10% to about 20%, about 10% to about 15%, or about 10% to about 12% uniformity.

In some embodiments, the included protective coating 200 and/or 250 may be formed or otherwise produced with different proportions of metals throughout the material, such as doped metals or graded metals contained within an alkali metal, wherein any metal may be in any chemically oxidized form (e.g., oxide, nitride, silicide, carbide, or a combination thereof). In one or more examples, the first deposited layer 210 is deposited to a first thickness, and the second deposited layer 220 is deposited to a second thickness, wherein the first thickness is less than or greater than the second thickness. For example, the first deposited layer 210 may be deposited during block 120 by two or more (3, 4, 5, 6, 7, 8, 9, 10, or more) ALD cycles to produce the same amount of sub-layers (e.g., one sub-layer per ALD cycle), and then the second deposited layer 220 may be deposited by one ALD cycle or a number of ALD cycles, wherein the number of ALD cycles is less than or greater than the number of ALD cycles used to deposit the first deposited layer 210. In other examples, the first deposition layer 210 may be deposited by CVD to a first thickness, and the second deposition layer 220 may be deposited by ALD to a second thickness that is less than the first thickness.

In other embodiments, the ALD process may be used to deposit the first deposition layer 210 and/or the second deposition layer 220, wherein the deposition material is doped by including a dopant precursor during the ALD process. In some instances, the dopant precursor may be included in a separate ALD cycle relative to the ALD cycle used to deposit the substrate material. In other instances, the dopant precursor may be co-injected with any of the chemical precursors used during the ALD cycle. In other embodiments, the dopant precursor may be injected independently of the chemical precursor during the ALD cycle. For example, an ALD cycle may include exposing an aerospace component to: a first precursor, pump-purge, a dopant precursor, pump-purge, a first reactant, and pump-purge to form a deposition layer. In some instances, an ALD cycle may include exposing an aerospace component to: a dopant precursor, pump-purge, a first precursor, pump-purge, a first reactant, and pump-purge to form a deposition layer. In other examples, an ALD cycle may include exposing an aerospace component to: a first precursor, a dopant precursor, a pump-purge, a first reactant, and a pump-purge to form a deposited layer.

In one or more embodiments, the first deposition layer 210 and/or the second deposition layer 220 contain one or more base materials and one or more doping materials. The base material is or contains aluminum oxide, chromium oxide, or a combination of aluminum oxide and chromium oxide. The doping material is or contains hafnium, hafnium oxide, yttrium, yttrium oxide, cerium, cerium oxide, silicon, silicon oxide, nitrides of the foregoing, or any combination of the foregoing. Any precursor or reactant described herein can be used as a doping precursor or dopant. Exemplary cerium precursors can be or include one or more tetrakis(2,2,6,6-tetramethyl-3,5-heptadienoate)cerium(IV) (Ce(TMHD) ₄ ), tri(cyclopentadienyl)cerium ((C ₅ H ₅ ) ₃ Ce), tri(propylcyclopentadienyl)cerium ([(C ₃ H ₇ )C ₅ H ₄ ] ₃ Ce), tri(tetramethylcyclopentadienyl)cerium ([(CH ₃ ) ₄ C ₅ H] ₃ Ce), or any combination of the foregoing.

The dopant material may have a concentration of about 0.01 atomic percent (at%), about 0.05 at%, about 0.08 at%, about 0.1 at%, about 0.5 at%, about 0.8 at%, about 1 at%, about 1.2 at%, about 1.5 at%, about 1.8 at%, or about 2 at% to about 2.5 at%, about 3 at%, about 3.5 at%, about 4 at%, about 5 at%, about 8 at%, about 10 at%, about 15 at%, about 20 at%, about 25 at%, or about 30 at% within the first deposition layer 210, the second deposition layer 220, the nanolaminate film stack 230, and/or the coalesced film 240. For example, the dopant material may have about 0.01 at % to about 30 at %, about 0.01 at % to about 25 at %, about 0.01 at % to about 20 at %, about 0.01 at % to about 15 at %, about 0.01 at % to about 12 at %, about 0.01 at % to about 10 at %, about 0.01 at % to about 8 at %, about 0.01 at % to about 5 at %, within the first deposition layer 210, the second deposition layer 220, the nanolaminate film stack 230, and/or the coalesced film 240. t%, about 0.01 at % to about 4 at %, about 0.01 at % to about 3 at %, about 0.01 at % to about 2.5 at %, about 0.01 at % to about 2 at %, about 0.01 at % to about 1.5 at %, about 0.01 at % to about 1 at %, about 0.01 at % to about 0.5 at %, about 0.01 at % to about 0.1 at %, about 0.1 at % to about 30 at %, about 0.1 at % to about 25 at %, about 0.1 at % to about 20 at %. %, about 0.1 at % to about 15 at %, about 0.1 at % to about 12 at %, about 0.1 at % to about 10 at %, about 0.1 at % to about 8 at %, about 0.1 at % to about 5 at %, about 0.1 at % to about 4 at %, about 0.1 at % to about 3 at %, about 0.1 at % to about 2.5 at %, about 0.1 at % to about 2 at %, about 0.1 at % to about 1.5 at %, about 0.1 at % to about 1 at %, about 0.1 at % to about 0. 5at %, about 1at % to about 30at %, about 1at % to about 25at %, about 1at % to about 20at %, about 1at % to about 15at %, about 1at % to about 12at %, about 1at % to about 10at %, about 1at % to about 8at %, about 1at % to about 5at %, about 1at % to about 4at %, about 1at % to about 3at %, about 1at % to about 2.5at %, about 1at % to about 2at %, or about 1at % to about 1.5at %.

In one or more embodiments, the protective coating 200 includes a nano-laminate film stack 230, the nano-laminate film stack 230 having a first deposited layer 210 and a second deposited layer 220, the first deposited layer containing aluminum oxide (or other base material) and the second deposited layer containing hafnium oxide (or other doping material), or the first deposited layer containing hafnium oxide (or other doping material) and the second deposited layer containing aluminum oxide (or other base material). In one or more examples, the protective coating 200 and/or 250 contains a combination of aluminum oxide and hafnium oxide, hafnium-doped aluminum oxide, hafnium aluminate, or any combination of the above. For example, the protective coating 200 includes a nano-laminate film stack 230, the nano-laminate film stack 230 having a first deposited layer 210 and a second deposited layer 220, the first deposited layer containing aluminum oxide and the second deposited layer containing hafnium oxide, or the first deposited layer containing hafnium oxide and the second deposited layer containing aluminum oxide. In other examples, the protective coating 250 includes a coalesced film 240 formed of layers of aluminum oxide or hafnium oxide. In one or more embodiments, the protective coating 200 or 250 has a concentration of about 0.01 at%, about 0.05 at%, about 0.08 at%, about 0.1 at%, about 0.5 at%, about 0.8 at%, or about 1 at% to about 1.2 at%, about 1.5 at%, about 1.8 at%, about 2 at%, about 2.5 at%, about 3 at%, about 3.5 at%, about 4 at%, about 4.5 at%, or about 5 at% within the nanolaminate film stack 230 or the coalesced film 240 containing aluminum oxide (or other base material). For example, the protective coating 200 or 250 may have a relative humidity of about 0.01 at % to about 10 at %, about 0.01 at % to about 8 at %, about 0.01 at % to about 5 at %, about 0.01 at % to about 4 at %, about 0.01 at % to about 3 at %, about 0.01 at % to about 2.5 at %, about 0.01 at % to about 2 at %, about 0.01 at % to about 1.5 at %, about 0.01 at % to about 1 at %, about 0.01 at % to about 0.5 at %, about 0.01 at % to about 0.1 at %, about 0.01 at % to about 0.05 at %, about 0.1 at % to about 5 at %, about 0.1 at % to about 4 at %, about 0.1 at % to about at% to about 3at%, about 0.1at% to about 2.5at%, about 0.1at% to about 2at%, about 0.1at% to about 1.5at%, about 0.1at% to about 1at%, about 0.1at% to about 0.5at%, about 0.5at% to about 5at%, about 0.5at% to about 4at%, about 0.5at% to about 3at%, about 0.5at% to about 2.5at%, about 0.5at% to about 2at%, about 0.5at% to about 1.5at%, about 0.5at% to about 1at%, about 1at% to about 5at%, about 1at% to about 4at%, about 1at% to about 3at%, about 1at% to about 2.5at%, about 1at% to about 2at%, or about 1at% to about 1.5at% hafnium (or other dopant material) concentration.

3A and 3B are schematic diagrams of an aerospace component 300 containing a protective coating 330 according to one or more embodiments described and discussed herein. FIG. 3A is a perspective view of the aerospace component 300, and FIG. 3B is a cross-sectional view of the aerospace component 300. As described and discussed herein, the protective coating 330 can be or include one or more nanolaminate film stacks, one or more coalesced films, or any combination of the foregoing. For example, the protective coating 330 can be or include the protective coating 200, which contains the nanolaminate film stack 230 (FIG. 2 (a)); and/or the protective coating 330 can be or include the protective coating 250, which contains the coalesced film (FIG. 2 (b)). Similarly, the aerospace component 300 can be or include the aerospace component 202 (FIG. 2). Aerospace components including aerospace component 300 as described or discussed herein may be or include one or more components of, or portions of, a turbine, an aircraft, a spacecraft, or other devices (e.g., a compressor, a pump, a turbofan, a supercharger, or the like) that may include one or more turbines. Exemplary aerospace components 300 may be or include a turbine blade, a turbine bucket, a support member, a frame, a rib, a fin, a columnar fin, a combustor fuel nozzle, a combustor shroud, an internal cooling passage, or any combination thereof.

The aerospace component 300 has one or more outside or exterior surfaces 310 and one or more inside or interior surfaces 320. The interior surfaces 320 may define one or more cavities 302 extending within or contained within the aerospace component 300. The cavities 302 may be passages, passages, spaces, etc. disposed between the interior surfaces 320. The cavities 302 may have one or more openings 304, 306, and 308. Each cavity 302 within the aerospace component 300 generally has an aspect ratio (e.g., length divided by width) greater than 1. The methods described and discussed herein provide steps for depositing and/or otherwise forming the protective coatings 200 and 250 on the interior surfaces 320 and/or within the chambers 302 with a high aspect ratio (greater than 1).

The aspect ratio of cavity 302 can be from about 2, about 3, about 5, about 8, about 10, or about 12 to about 15, about 20, about 25, about 30, about 40, about 50, about 65, about 80, about 100, about 120, about 150, about 200, about 250, about 300, about 500, about 800, about 1,000, or more. For example, the aspect ratio of cavity 302 can be from about 2 to about 1,000, about 2 to about 500, about 2 to about 200, about 2 to about 150, about 2 to about 120, about 2 to about 100, about 2 to about 80, about 2 to about 50, about 2 to about 40, about 2 to about 30, about 2 to about 20, about 2 to about 10, about 2 to about 8, about 5 to about 1,000, about 5 to about 500, about 5 to about 200, about 5 to about 150, about 5 to about 120, about 5 to about 100, about 5 to about 80, about 5 to about 50, about 5 to about 40, about 5 to about 30, about 5 to about 20 , about 5 to about 10, about 5 to about 8, about 10 to about 1,000, about 10 to about 500, about 10 to about 200, about 10 to about 150, about 10 to about 120, about 10 to about 100, about 10 to about 80, about 10 to about 50, about 10 to about 40, about 10 to about 30, about 10 to about 20, about 20 to about 1,000, about 20 to about 500, about 20 to about 200, about 20 to about 150, about 20 to about 120, about 20 to about 100, about 20 to about 80, about 20 to about 50, about 20 to about 40, or about 20 to about 30.

The aerospace component 300 and any of its surfaces, including one or more outside or external surfaces 310 and/or one or more inside or internal surfaces 320, can be made of, contain, or otherwise include one or more metals, such as nickel, aluminum, chromium, iron, titanium, hafnium, one or more nickel superalloys, one or more Inconel alloys, one or more Hastelloy alloys, or any combination thereof. The protective coating 330 can be deposited, formed, or otherwise created on any of the surfaces of the aerospace component 300, including one or more outside or external surfaces 310 and/or one or more inside or internal surfaces 320.

The protective coating as described and discussed herein may be or include one or more of a laminated film stack, a coalesced film, a graded composition, and/or a monolithic film deposited or otherwise formed on any surface of an aerospace component. In some instances, the protective coating contains from about 1% to about 100% chromium oxide. The protective coating is conformal and substantially follows the surface topology to coat rough surface features, including surface features in open holes, blind holes, and non-line-of-sight areas of the surface. The protective coating does not substantially increase the surface roughness, and in some embodiments, the protective coating can reduce the surface roughness by conformally coating the roughness until it coalesces. The protective coating may contain particles from the deposition that are substantially larger than the roughness of the aerospace component, but these particles are considered to be separated from the monolithic film. The protective coating is substantially well adhered and pinhole-free. The thickness of the protective coating varies within 1σ of 40%. In one or more embodiments, the thickness variation is less than 1-σ of 20%, 10%, 5%, 1%, or 0.1%.

Protective coatings can provide corrosion and oxidation protection when aerospace components are exposed to air, oxygen, sulfur and/or sulfur compounds, acids, bases, salts (e.g., Na, K, Mg, Li, or Ca salts), or any combination of the foregoing.

One or more embodiments described herein include methods of preserving an underlying chromium-containing alloy using a method of producing alternating nanolaminates of a first material (e.g., chromium oxide, aluminum oxide, and/or aluminum nitride) and another secondary material. The secondary material may be or include aluminum oxide, aluminum nitride, aluminum oxynitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium silicate, hafnium silicide, hafnium nitride, titanium oxide, titanium nitride, titanium silicide, titanium silicate, dopants thereof, alloys thereof, or any combination thereof. The resulting film may be used as a nanolaminate film stack or the film may undergo an annealing wherein the high temperature coalesces the film into a single structure in which the new crystalline assembly enhances the integrity and protection of this overlying film.

In a particular embodiment, a chromium precursor (at a temperature of about 0°C to about 250°C) is delivered to an aerospace component via vapor phase delivery for a predetermined pulse length of 5 seconds. During this process, the deposition reactor is operated under a nitrogen carrier gas flow (about 1,000 seem total) with the chamber maintained at a predetermined temperature of about 350°C and a pressure of about 3.5 Torr. Following the pulse of the chromium precursor, the chamber is then pumped and purged of all necessary gases and byproducts for a determined amount of time. Subsequently, water is pulsed into the chamber at a chamber pressure of about 3.5 Torr for 0.1 seconds. Additional chamber purges (or pumping/purging) are then performed to remove any excess reactants and reaction byproducts in the reactor. This process is repeated as many times as necessary to achieve the desired film thickness for the target CrOx film.

For the secondary film (example: aluminum oxide), the precursor trimethylaluminum (at a temperature of about 0°C to about 30°C) is delivered to the aerospace component via vapor phase delivery for a predetermined pulse length of 0.1 seconds. During this process, the deposition reactor is operated under a nitrogen carrier gas flow (about 100 seem total) with the chamber maintained at a predetermined temperature of about 150°C to about 350°C and a pressure of about 1 Torr to about 5 Torr. After the pulse of trimethylaluminum, the chamber is then evacuated and purged of all necessary gases and byproducts for a determined amount of time. Subsequently, water vapor is pulsed into the chamber at a chamber pressure of about 3.5 Torr for about 0.1 seconds. Additional chamber purges are then performed to remove any excess reactants and reaction byproducts in the reactor. This process is repeated as many times as necessary to achieve the desired film thickness for the target Al ₂ O ₃ film. The aerospace component is then subjected to an annealing furnace at a temperature of about 500°C for about one hour under an inert nitrogen flow of about 500 seem.

Doping/alloying ALP layer process

One or more embodiments described herein include methods for preserving underlying aerospace components by using a doped chromium-containing film. The film is or includes a chromium-containing film produced by using a chromium precursor, and one or more oxygen sources or oxidants (for chromium oxide deposition), nitrogen sources or nitriding agents (for chromium nitride deposition), one or more carbon sources or carbon precursors (for chromium carbide deposition), silicon sources or silicon precursors (for chromium silicide deposition), or any combination thereof. The doping precursor (or dopant) may be or include a source of aluminum, yttrium, hafnium, silicon, tantalum, zirconium, strontium, lanthanum, neodymium, holmium, barium, lutetium, dysprosium, samarium, terbium, erbium, thulium, titanium, niobium, manganese, scandium, europium, tin, cerium, or any combination thereof. The precursor used may be or include, but is not limited to, one or more chromium precursors, as described and discussed above. A chromium precursor may be used during the deposition process to produce a doped film containing a ternary material (e.g., YCrO or CrAlO). The resulting film may be used as a nanolaminate film stack or the film may undergo an anneal where a high temperature coalesces the film into a single structure where the new crystalline assembly enhances the integrity and protection of this overlying film.

In a specific embodiment, the chromium precursor bis(1,4-di-tert-butyldiazadienylchromium(II)) is delivered to the aerospace component via vapor phase delivery (at a temperature of about 0 to about 250°C) for a predetermined pulse length of 5 seconds. During this process, the deposition reactor is operated under a nitrogen carrier gas flow of about 1,000 seem, with the chamber maintained at a predetermined temperature of about 350°C and a pressure of about 3.5 Torr. After the pulse of the chromium precursor, the chamber is evacuated and purged of all necessary gases and byproducts for a determined amount of time. Subsequently, a second reactant, water, is pulsed into the chamber at a chamber pressure of about 3.5 Torr for 0.1 seconds. Then, a second chamber purge is performed to remove any excess reactants and reaction byproducts in the reactor.

This chromium precursor/pump-purge/water/pump-purge sequence is repeated as many times as necessary to achieve the desired film thickness of the target CrOx film. This process forms a first CrOx layer stack having a desired thickness.

After the first CrOx stack is deposited, the third reactant, tetrakis(ethylmethylamino)hafnium (TEMAH), is pulsed into the chamber for 5 seconds at a chamber pressure of about 1.6 torr. Then, a final chamber pumping/purge is performed to remove any excess reactants and reaction byproducts in the reactor. Subsequently, a second reactant, water, is pulsed into the chamber for 3 seconds at a chamber pressure of about 1.2 torr. A second chamber pumping/purge is then performed to remove any excess reactants and reaction byproducts in the reactor. This single sequence forms a second HfOx stack with a thickness of a monolayer (HfOx).

This first CrOx/second HfOx layer stack sequence is repeated as many times as necessary to achieve the desired film thickness of the target Hf-doped chromium oxide film (CrOx:Hf). The resulting CrOx:Hf film can be used as a nanolaminated film stack or film and can undergo annealing in which high temperature activates the diffusion of Hf into the CrOx layer, wherein the more uniform Hf distribution in the CrOx:Hf film enhances the integrity and protection of this capping film.

In a particular embodiment, a selected aluminum precursor, trimethylaluminum (TMAl), is delivered to the aerospace component via vapor phase delivery (at a temperature of about 0°C to about 30°C) for a predetermined pulse length of about 0.1 seconds to about 1 second. During this process, the deposition reactor is operated under a nitrogen carrier gas flow of about 100 seem, with the chamber maintained at a predetermined temperature of about 150°C to about 350°C and a pressure of about 1 Torr to about 5 Torr. After the pulse of trimethylaluminum, the chamber is then pumped and purged of all necessary gases and byproducts for a determined amount of time. Subsequently, water vapor is pulsed into the chamber at a chamber pressure of about 1 Torr to about 5 Torr for 3 seconds. An additional chamber purge is then performed to remove any excess reactants and reaction byproducts in the reactor. This aluminum precursor/pump-purge/water/pump-purge sequence is repeated as many times as necessary to achieve a desired film thickness for the target AlOx (e.g., Al ₂ O ₃ ) film. This process forms a first AlOx layer stack having a desired thickness.

After the first AlOx stack is deposited, a third reactant, tetrakis(ethylmethylamino)hafnium (TEMAH), is pulsed into the chamber at a chamber pressure of about 1.6 Torr for about 5 seconds. This is followed by a final chamber pump/purge to remove any excess reactants and reaction byproducts in the reactor. Subsequently, a second reactant, water, is pulsed into the chamber at a chamber pressure of about 1.2 Torr for about 3 seconds. This is followed by a second chamber pump/purge to remove any excess reactants and reaction byproducts in the reactor. This single sequence forms a second HfOx stack having a monolayer (HfOx) thickness.

This first AlOx/second HfOx layer stack sequence is repeated as many times as necessary to achieve the desired film thickness of the target Hf-doped aluminum oxide film (AlOx:Hf). In some examples, the resulting AlOx:Hf film is used as a nanolaminate film stack. In other examples, the resulting AlOx:Hf film undergoes annealing in which high temperature activates the diffusion of Hf into the AlOx layer, where a more uniform Hf distribution in the AlOx:Hf film enhances the integrity and protection of this capping film.

SEM shows a cross section of an ALD as-grown Hf-doped Al ₂ O ₃ layer on a Si aerospace component. SEM shows a cross section of an Hf-doped Al ₂ O ₃ layer with a Hf concentration of about 0.1 at %. The total Al ₂ O ₃ :Hf film thickness is about 140 nm. The film contains six Al _{2 O 3 /HfO 2 layer stacks. The thickness of a single Al 2 O 3 / HfO 2 layer} stack is about 23 nm. SEM shows a cross section of an Hf-doped Al ₂ O ₃ layer with a Hf concentration of about 0.5 at %. The total Al ₂ O ₃ :Hf film thickness is about 108 nm. The film contains twenty-one Al ₂ O ₃ /HfO ₂ layer stacks. The thickness of a single Al ₂ O ₃ /HfO ₂ layer stack is about 5.1 nm.

For samples doped with Hf at about 0.1 at%, visual distinction of the HfO ₂ and Al ₂ O ₃ layers is visible on the SEM cross section. However, the SEM resolution (10 nm) limits the visual distinction of the HfO ₂ and Al ₂ O ₃ layers to samples doped with Hf at about 0.5 at%. SIMS was used to determine the concentration depth profile of ALD native Hf-doped Al ₂ O ₃ layers on aerospace components. The SIMS concentration depth profile of the Hf-doped Al ₂ O ₃ layers is a Hf concentration of about 0.1 at%. The film contains six Al ₂ O ₃ /HfO ₂ layer stacks. The SIMS concentration depth profile of the Hf-doped Al ₂ O ₃ layers is a Hf concentration of about 0.5 at%. The film contains twenty-one Al ₂ O ₃ /HfO ₂ layer stacks.

Rutherford backscatterlng spectrometry (RBS) provides compositional analysis data for ALD native Hf-doped _{Al2O3 layers} . RBS analysis demonstrates that bulk _Al2O3 : _Hf layers with six _Al2O3 / _{HfO2 stacks have} an Hf concentration of about 0.1 at%, and bulk _Al2O3 :Hf layers with twenty-one _{Al2O3 / HfO2 stacks} have an Hf concentration of about 0.5 at%.

In one or more embodiments, a protective coating comprising a chromium-containing material is desirable for many applications to form a stable chromium oxide in air to protect the surface from oxidation, acid attack, and sulfur corrosion. In the case of Fe, Co, and/or Ni-based alloys, chromium oxide (and aluminum oxide) is selectively formed to produce a passivated surface. However, before forming this selective oxidation layer, the other metal elements are oxidized until the chromium oxide forms a continuous layer.

After the dense chromium oxide layer is formed, exposure to high temperatures in air (e.g., greater than 500°C) causes the chromium oxide scale to thicken as chromium diffuses from the bulk metal into the scale and oxygen diffuses from the air into the scale. Over time, the growth rate of the scale slows as the scale thickens because (1) oxygen diffuses more slowly and (2) the chromium in the bulk alloy becomes depleted. For alloys, if the chromium concentration drops below a threshold, other oxides may begin to form that can cause the previous protective scale to flake off or fail.

In order to extend the life of the chromium-containing alloy, one or more of the following methods may be used. In one or more embodiments, the method may include depositing an oxide layer that matches the composition and crystal structure of the native oxide to produce a protective coating. In other embodiments, the method may include depositing an oxide layer having a different crystal structure than the native oxide to produce a protective coating. In some embodiments, the method may include depositing an oxide layer with additional dopants to produce a protective coating that would not be present in the native oxide. In other embodiments, the method may include depositing another layer (e.g., silicon oxide or aluminum oxide) as a cap layer or in a multilayer stack to produce a protective coating.

In one or more embodiments of the method, non-native oxide can be initially deposited on the surface of the metal surface of aerospace parts or other substrates that effectively thicken oxide, thereby slowing down the oxygen diffusion to the metal surface and producing the absolute thickness growth of the slower oxide film. In some instances, the benefits of this method can be expected in the context of a parabolic oxide scale growth curve. At a thicker scale (e.g., greater than 0.5 micron to about 1.5 microns), the rate of scale thickening is reduced relative to initial growth. Before growing a thick scale, an oxide film with a thickness of about 100nm, about 200nm or about 300nm to about 1 micron, about 2 microns or about 3 microns is deposited. In a given time period, the effective growth rate of the first thickness of about 0.5 micron to about 1 micron of native scale may be much slower. In turn, the consumption rate of chromium from the substrate may be slower, and the time when the surface can be exposed to the environment can be longer.

Oxygen diffusion can be further slowed by depositing a predetermined chromium oxide crystal structure, such as an amorphous state. Oxygen can diffuse faster along grain boundaries than in bulk crystals of chromium oxide, so minimizing grain boundaries can be beneficial in slowing oxygen diffusion. In turn, scale growth can be slower and the surface can be exposed to the environment for a longer period of time.

In other embodiments, the method may include incorporating one or more dopants into the deposited oxide while producing the protective coating. The dopant may be or include a source of aluminum, yttrium, hafnium, silicon, tantalum, zirconium, strontium, lanthanum, neodymium, holmium, barium, lutetium, dysprosium, samarium, terbium, erbium, thulium, titanium, niobium, manganese, scandium, europium, tin, cerium, or any combination of the foregoing. The dopant may segregate to the grain boundaries and alter the grain boundary diffusion rate to slow the growth rate of the oxide scale.

In one or more embodiments, an aerospace component includes a coating disposed on a surface of a substrate. The surface of the substrate includes or contains nickel, a nickel superalloy, aluminum, chromium, iron, titanium, hafnium, an alloy of the foregoing, or any combination of the foregoing. The coating has a thickness of less than 10 μm and contains an aluminum oxide layer, and in some examples, the surface of the aerospace component is an inner surface within a cavity of the aerospace component. The cavity may have an aspect ratio of about 5 to about 1,000 and the coating may have a uniformity of less than 30% of the thickness across the inner surface.

Embodiments of the present disclosure further relate to any one or more of the following paragraphs:

1. A method for depositing a coating on an aerospace component, comprising: sequentially exposing the aerospace component to a chromium precursor and a reactant to form a chromium-containing layer on a surface of the aerospace component by an atomic layer deposition process.

2. A method for depositing a coating on an aerospace component, comprising: forming a nanolaminate film stack on a surface of the aerospace component, wherein the nanolaminate film stack comprises alternating layers of a chromium-containing layer and a second deposited layer; sequentially exposing the aerospace component to a chromium precursor and a first reactant to form a chromium-containing layer on the surface by atomic layer deposition, wherein the chromium-containing layer comprises chromium oxide, chromium nitride, or a combination of the foregoing; and sequentially exposing the aerospace component to a metal or silicon precursor and a second reactant to form a second deposited layer on the surface by atomic layer deposition, wherein the second deposited layer comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate, or any combination of the foregoing.

3. The method of paragraph 1 or 2, wherein the chromium precursor comprises bis(cyclopentadienyl)chromium, bis(pentamethylcyclopentadienyl)chromium, bis(isopropylcyclopentadienyl)chromium, bis(ethylbenzene)chromium, hexacarbonyl chromium, chromium acetylacetonate, chromium hexafluoroacetylacetonate, diazadiene chromium, isomers thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof.

4. The method of paragraph 3, wherein the diazadiene chromium has the following chemical formula:

wherein each R and R′ is independently selected from H, C1-C6 alkyl, aryl, acyl, alkylamide, hydrazide, silyl, aldehyde, keto, C2-C4 alkenyl, alkynyl or a substituent thereof.

5. The method of paragraph 4, wherein each R is independently a C1-C6 alkyl group selected from methyl, ethyl, propyl, butyl or isomers thereof, and R′ is H.

6. The method of paragraph 4, wherein R is tert-butyl and R′ is H.

7. The method of paragraph 4, wherein the diazadienyl chromium is bis(1,4-di-tert-butyldiazadienyl)chromium(II).

8. The method of any of paragraphs 1 to 7, wherein the reactant comprises a reducing agent and the chromium-containing layer comprises metallic chromium.

9. The method of paragraph 8, wherein the reducing agent comprises hydrogen ( _H2 ), ammonia, hydrazine, hydrazine, alcohol, cyclohexadiene, dihydropyrazine, aluminum-containing compounds, extensions thereof, salts thereof, plasma derivatives thereof, or any combination thereof.

10. The method of any of paragraphs 1 to 9, wherein the reactant comprises an oxidant and the chromium-containing layer comprises chromium oxide.

11. The method of paragraph 10, wherein the oxidant comprises water, oxygen ( _O2 ), atomic oxygen, ozone, nitrous oxide, peroxide, alcohol, plasma thereof, or any combination thereof.

12. The method of any of paragraphs 1 to 11, wherein the reactant comprises a nitriding agent and the chromium-containing layer comprises chromium nitride.

13. The method of paragraph 12, wherein the nitriding agent comprises ammonia, atomic nitrogen, hydrazine, a plasma of the foregoing, or any combination thereof.

14. The method of any of paragraphs 1 to 13, wherein the reactant comprises a carbon precursor or a silicon precursor, and the chromium-containing layer comprises chromium carbide or chromium silicide.

15. The method of paragraph 14, wherein the carbon precursor comprises an alkane, an alkene, an alkyne, a substituent thereof, a plasma thereof, or any combination thereof; and the silicon precursor comprises a silane, a disilane, a substituted silane, a plasma thereof, or any combination thereof.

16. The method of any of paragraphs 1 to 15, further comprising forming a nanolaminate film stack on a surface of the aerospace component, wherein the nanolaminate film stack comprises alternating layers of chromium-containing layers and second deposited layers.

17. The method of paragraph 16, wherein the second deposited layer comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate, or any combination thereof.

18. The method of paragraph 16, wherein the chromium-containing layer comprises chromium oxide, chromium nitride, or a combination thereof; and wherein the second deposited layer comprises aluminum oxide, silicon nitride, hafnium oxide, hafnium silicate, or any combination thereof.

19. The method of paragraph 16, wherein the alternating layers in the nanolaminate film stack comprise from 1 pair to about 50 pairs of the chromium-containing layer and the second deposited layer.

20. The method of paragraph 16, wherein the second deposited layer is deposited by atomic layer deposition.

21. The method of paragraph 16, further comprising annealing the aerospace component and converting the nanolaminate film stack to a coalesced film.

22. The method of any of paragraphs 1 to 21, wherein the aerospace component is a turbine blade, a turbine bucket, a support member, a frame, a rib, a fin, a columnar fin, a combustor fuel nozzle, a combustor shroud, an internal cooling passage, or any combination thereof.

23. The method of any of paragraphs 1 to 22, wherein the surface of the aerospace component is an interior surface of the aerospace component.

24. The method of any of paragraphs 1 to 23, wherein the surface of the aerospace component is an exterior surface of the aerospace component.

25. The method of any of paragraphs 1 to 24, wherein the surface of the aerospace component comprises nickel, a nickel superalloy, aluminum, chromium, iron, titanium, hafnium, alloys thereof, or any combination thereof.

26. An aerospace component comprising: a surface comprising nickel, a nickel superalloy, aluminum, chromium, iron, titanium, hafnium, alloys of the foregoing, or any combination of the foregoing; and a coating having a thickness of less than 10 μm and disposed on the surface, wherein the coating comprises a chromium-containing layer, and wherein the chromium-containing layer comprises metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium silicide, or any combination of the foregoing.

27. An aerospace component comprising: a surface comprising nickel, a nickel superalloy, aluminum, chromium, iron, titanium, hafnium, alloys of the foregoing, or any combination of the foregoing; and a coating having a thickness of less than 10 μm and disposed on the surface, wherein the coating comprises aluminum oxide.

28. An aerospace component comprising: a surface comprising nickel, a nickel superalloy, aluminum, chromium, iron, titanium, hafnium, alloys of the foregoing, or any combination of the foregoing; and a coating on the surface, wherein the coating is deposited by atomic layer deposition and comprises a chromium-containing layer, and wherein the chromium-containing layer comprises metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium silicide, or any combination of the foregoing.

29. An aerospace component as described in any of paragraphs 26 to 28, wherein the surface of the aerospace component is an interior surface within a cavity of the aerospace component, wherein the cavity has an aspect ratio of about 5 to about 1,000, and the coating has a uniformity across the interior surface of less than 30% of the thickness.

30. The aerospace component of any of paragraphs 26 to 29, wherein the aerospace component is a turbine blade, a turbine bucket, a support member, a frame, a rib, a fin, a columnar fin, a combustor fuel nozzle, a combustor shroud, an internal cooling passage, or any combination thereof.

31. The aerospace component of any of paragraphs 26 to 30, wherein the surface has cavities having an aspect ratio of greater than 5 to 1,000.

32. A method for depositing a coating on an aerospace component, comprising: exposing the aerospace component to a first precursor and a first reactant to form a first deposition layer on the surface of the aerospace component by a chemical vapor deposition (CVD) process or a first atomic layer deposition (ALD) process; and exposing the aerospace component to a second precursor and a second reactant to form a second deposition layer on the first deposition layer by a second ALD process, wherein the first deposition layer and the second deposition layer have different compositions from each other.

33. A method for depositing a coating on an aerospace component, comprising: forming a nanolaminate film stack on a surface of the aerospace component, wherein the nanolaminate film stack comprises alternating layers of a first deposited layer and a second deposited layer; sequentially exposing the aerospace component to a first precursor and a first reactant to form the first deposited layer on the surface by atomic layer deposition, wherein the first deposited layer comprises chromium oxide, chromium nitride, aluminum oxide, aluminum nitride, or any combination of the foregoing; and sequentially exposing the aerospace component to a second precursor and a second reactant to form a second deposited layer on the first deposited layer by atomic layer deposition, wherein the second deposited layer comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate, or any combination of the foregoing, and wherein the first deposited layer and the second deposited layer have different compositions from each other.

34. The method of paragraphs 32 or 33, wherein the first deposited layer is formed by an ALD process and the method further comprises sequentially exposing the aerospace component to a first precursor and a first reactant to form the first deposited layer.

35. A method as described in paragraph 34, wherein each cycle of the first ALD process includes exposing the aerospace component to a first precursor, performing a pump-purge, exposing the aerospace component to a first reactant, and performing a pump-purge; and each cycle is repeated from 2 to about 500 times to form the first deposition layer before forming the second deposition layer.

36. The method of any of paragraphs 32 to 35, wherein the first deposited layer is formed by a CVD process and the method further comprises simultaneously exposing the aerospace component to a first precursor and a first reactant to form the first deposited layer.

37. A method as described in any of paragraphs 32 to 36, wherein the first deposited layer comprises chromium oxide, chromium nitride, aluminum oxide or aluminum nitride, wherein the second deposited layer comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate or any combination of the foregoing, and wherein if the first deposited layer comprises aluminum oxide or aluminum nitride, then the second deposited layer does not comprise aluminum oxide and aluminum nitride.

38. The method of any of paragraphs 32 to 37, wherein the first precursor comprises a chromium precursor or an aluminum precursor, and the first reactant comprises an oxidizing agent, a nitriding agent, or a combination thereof.

39. The method of any of paragraphs 32 to 38, wherein the second precursor comprises an aluminum precursor or a hafnium precursor, and the second reactant comprises an oxidizing agent, a nitriding agent, or a combination thereof.

40. The method of any of paragraphs 32 to 39, wherein the first precursor comprises bis(cyclopentadienyl)chromium, bis(pentamethylcyclopentadienyl)chromium, bis(isopropylcyclopentadienyl)chromium, bis(ethylbenzene)chromium, hexacarbonylchromium, chromium acetylacetonate, chromium hexafluoroacetylacetonate, diazadienylchromium, isomers thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof.

41. The method of paragraph 40, wherein the diazadienylchromium has the following chemical formula:

wherein each R and R′ is independently selected from H, C1-C6 alkyl, aryl, acyl, alkylamide, hydrazide, silyl, aldehyde, keto, C2-C4 alkenyl, alkynyl or a substituent thereof.

42. The method of paragraph 40, wherein each R is independently a C1-C6 alkyl group selected from methyl, ethyl, propyl, butyl, or isomers thereof, and R′ is H.

43. The method of paragraph 40, wherein R is tert-butyl and R' is H.

44. The method of paragraph 40, wherein the diazadienylchromium is bis(1,4-di-tert-butyldiazadienyl)chromium(II).

45. The method of any of paragraphs 32 to 44, wherein the first precursor or the second precursor comprises an aluminum precursor, and wherein the aluminum precursor comprises tri(alkyl)aluminum, tri(alkoxy)aluminum, aluminum diketonate, complexes thereof, extensions thereof, salts thereof, or any combination thereof.

46. The method of paragraph 45, wherein the aluminum precursor comprises trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, trimethoxyaluminum, triethoxyaluminum, tripropoxyaluminum, tributoxyaluminum, aluminum acetylacetonate, acetylated aluminum hexafluoroethanedione, tris-di-pivaloylmethylaluminum, isomers thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof.

47. The method of any of paragraphs 32 to 46, wherein the first precursor or the second precursor comprises a hafnium precursor, and wherein the hafnium precursor comprises bis(methylcyclopentadienyl)dimethyl hafnium, bis(methylcyclopentadienyl)methylmethoxy hafnium, bis(cyclopentadienyl)dimethyl hafnium, tetra(tert-butoxy)hafnium, isopropoxy hafnium, tetrakis(dimethylamino)hafnium (TDMAH), tetrakis(diethylamino)hafnium (TDEAH), tetrakis(ethynylmethylamino)hafnium (TEMAH), isomers thereof, complexes thereof, extensions thereof, salts thereof, or any combination thereof.

48. The method of any of paragraphs 32 to 47, wherein the nanolaminate film stack comprises a first deposited layer and a second deposited layer, and the method further comprises depositing from 2 to about 500 pairs of the first deposited layer and the second deposited layer while increasing the thickness of the nanolaminate film stack.

49. The method of paragraph 48, wherein each pair of the first deposition layer and the second deposition layer has a thickness of about 0.2 nm to about 50 nm.

50. The method of paragraph 48, further comprising annealing the aerospace component and converting the nanolaminate film stack to a coalesced film.

51. The method of paragraph 47, wherein the first deposited layer comprises aluminum oxide and the second deposited layer comprises hafnium oxide, and wherein the concentration of hafnium within the nanolaminate film stack is from about 0.01 at % to about 10 at %.

52. The method of paragraph 48, wherein the nanolaminate film stack has a thickness of about 1 nm to about 5,000 nm.

53. The method of any of paragraphs 32 to 52, wherein the aerospace component is a turbine blade, a turbine bucket, a support member, a frame, a rib, a fin, a columnar fin, a combustor fuel nozzle, a combustor shroud, an internal cooling passage, or any combination thereof.

54. The method of any of paragraphs 32 to 53, wherein the surface of the aerospace component is an interior surface of the aerospace component, and wherein the surface of the aerospace component comprises nickel, a nickel superalloy, aluminum, chromium, iron, titanium, hafnium, alloys thereof, or any combination thereof.

55. The method of any of paragraphs 32 to 54, wherein the surface of the aerospace component has cavities having an aspect ratio of greater than 5 to 1,000.

56. An aerospace component comprising: a surface comprising nickel, a nickel superalloy, aluminum, chromium, iron, titanium, hafnium, alloys of the foregoing, or any combination of the foregoing; and a coating disposed on the surface, wherein the coating comprises a nanolaminate film stack, the nanolaminate film stack comprising alternating layers of a first deposited layer and a second deposited layer; wherein the first deposited layer comprises chromium oxide, chromium nitride, aluminum oxide, aluminum nitride, or any combination of the foregoing; wherein the second deposited layer comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate, or any combination of the foregoing; wherein the first deposited layer and the second deposited layer have different compositions from each other; and wherein the nanolaminate film stack has a thickness of about 1 nm to about 5,000 nm.

57. The aerospace component of paragraph 56, wherein the aerospace component is a turbine blade, a turbine bucket, a support member, a frame, a rib, a fin, a columnar fin, a combustor fuel nozzle, a combustor shroud, an internal cooling passage, or any combination thereof.

58. The aerospace component of paragraphs 56 or 57, wherein the surface of the aerospace component is an interior surface within a cavity of the aerospace component.

59. The aerospace component of any of paragraphs 56 to 58, wherein the cavity has an aspect ratio of about 5 to about 1,000.

60. The aerospace component of any of paragraphs 56 to 59, wherein the coating has a uniformity across the inner surface that is less than 30% of the thickness across the inner surface.

Although the foregoing is directed to the embodiments of the present disclosure, other and further embodiments may be designed without departing from the basic scope of the present disclosure, and the scope is determined by the appended claims. All documents described herein are incorporated herein by reference, including any priority documents and/or test procedures that are not inconsistent with this document. As is apparent from the general description and specific embodiments above, although various forms of the present disclosure have been shown and described, various modifications may be made without departing from the spirit and scope of the present disclosure. Therefore, it is not intended that the present disclosure be limited thereto. Similarly, for purposes of U.S. law, the term "comprising" is considered to be synonymous with the term "including". Similarly, whenever a transition phrase "comprising" is added to a component, element, or a group of elements, it should be understood that we may also expect to have a transition phrase in front of a narration component, element, or several elements, "substantially consisting of...", "consisting of...", "selected from a group consisting of..." or "is" the same composition or a group of elements, and vice versa.

Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be understood that, unless otherwise indicated, ranges including combinations of any two values, for example, a range of any lower value combined with any higher value, a combination of any two lower values, and/or a combination of any two higher values, are contemplated. Certain lower limits, upper limits, and ranges appear in one or more of the following claims.

Claims (20)

1. A method of depositing a coating on an aerospace component, comprising:

exposing the aerospace component to a chromium precursor and a reactant to form a chromium-containing layer on a surface of the aerospace component by a vapor deposition process; and

forming a nanolaminate film stack on the surface of the aerospace component, wherein the nanolaminate film stack comprises alternating layers of the chromium-containing layer and a second deposited layer.

2. The method of claim 1, wherein the vapor deposition process is a chemical vapor deposition process.

3. The method of claim 1, wherein the vapor deposition process is an atomic layer deposition process.

4. The method of claim 1, wherein the chromium precursor comprises bis (cyclopentadiene) chromium, bis (pentamethylcyclopentadiene) chromium, bis (isopropylcyclopentadiene) chromium, bis (ethylbenzene) chromium, chromium hexacarbonyl, chromium acetylacetonate, chromium hexafluoroacetylacetonate, chromium diazadienes, isomers of the foregoing, complexes of the foregoing, abducts (abducts) of the foregoing, salts of the foregoing, or any combination of the foregoing.

5. The method of claim 4, wherein the diazadienchrome has the formula:

wherein each R and R' is independently selected from H, C C6 alkyl, aryl, acyl, alkylamide, hydrazide, silyl, aldehyde, ketone, C2C 4 alkenyl, alkynyl, or substituents of the foregoing.

6. The method of claim 1, wherein the reactant comprises an oxidizing agent and the chromium-containing layer comprises chromium oxide, and wherein the oxidizing agent comprises water, oxygen (O ₂ ) Atomic oxygen, ozone, nitrous oxide, peroxides, alcohols, plasmas of the foregoing, or any combination thereof.

7. The method of claim 1, wherein the second deposited layer comprises aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon carbide, yttrium oxide, yttrium nitride, yttrium silicon nitride, hafnium oxide, hafnium nitride, hafnium silicide, hafnium silicate, titanium oxide, titanium nitride, titanium silicide, titanium silicate, or any combination thereof.

8. The method of claim 1, further comprising annealing the aerospace component and converting the nanolaminate film stack into a polymeric film.

9. The method of claim 1, wherein the aerospace component is a turbine blade, a turbine vane, a support member, a frame, a rib, a fin, a pillar fin, a combustor fuel nozzle, a combustor shroud, an internal cooling channel, or any combination thereof.

10. The method of claim 1, wherein the surface of the aerospace component is an interior surface of the aerospace component, and wherein the surface of the aerospace component comprises nickel, nickel superalloy, aluminum, chromium, iron, titanium, hafnium, alloys thereof, or any combination thereof.

11. A method of depositing a coating on an aerospace component, comprising:

a chromium-containing layer comprising chromium oxide is deposited on a surface of the aerospace component, the surface comprising aluminum, and the depositing is performed by a vapor deposition process, wherein the aerospace component is exposed to a chromium precursor and an oxidizing agent during the vapor deposition process to form the chromium-containing layer.

12. The method of claim 11, wherein the oxidant comprises water, oxygen (O ₂ ) Atomic oxygen, ozone, nitrous oxide, peroxides, alcohols, plasmas of the foregoing, or any combination thereof.

13. The method of claim 11, wherein the vapor deposition process is a chemical vapor deposition process.

14. The method of claim 11, wherein the vapor deposition process is an atomic layer deposition process.

15. The method of claim 11, wherein the surface of the aerospace component is an interior surface of the aerospace component, and wherein the aerospace component is a turbine blade, a turbine bucket, a support member, a frame, a rib, a fin, a cylindrical fin, a combustor fuel nozzle, a combustor shroud, an internal cooling channel, or any combination thereof.

16. A method of depositing a coating on an aerospace component, comprising:

exposing the aerospace component to a chromium precursor and an oxidizing agent to form a chromium-containing layer comprising chromium oxide on a surface of the aerospace component by a vapor deposition process, wherein the chromium precursor comprises a diazadienchronium having the formula:

wherein each R and R' is independently selected from H, C C6 alkyl, aryl, acyl, alkylamide, hydrazide, silyl, aldehyde, ketone, C2C 4 alkenyl, alkynyl, or substituents of the foregoing.

17. The method of claim 16, wherein the oxidant comprises water, oxygen (0 ₂ ) Atomic oxygen, ozone, nitrous oxide, peroxides, alcohols, plasmas of the foregoing, or any combination thereof.

18. The method of claim 16, wherein the vapor deposition process is a chemical vapor deposition process.

19. The method of claim 16, wherein the vapor deposition process is an atomic layer deposition process.

20. The method of claim 16, wherein the surface of the aerospace component is an interior surface of the aerospace component, and wherein the aerospace component is a turbine blade, a turbine bucket, a support member, a frame, a rib, a fin, a cylindrical fin, a combustor fuel nozzle, a combustor shroud, an internal cooling channel, or any combination thereof.